In semiconductor components, in particular in power semiconductor components such as power MOSFETs, the on resistance and the breakdown voltage are important parameters. In conventional semiconductor components the two quantities are coupled via the doping level, such that a lower breakdown voltage has to be accepted for a lower on resistance. One possibility of eliminating this coupling is constituted by compensation components, in which are arranged in the, for example, n-conducting drift path p-conducting compensation regions which compensate for charges introduced into the drift zone by using mirror charges in order in this way to enable an increase in the doping at the drift zone and thus to set the on resistance with the voltage remaining constant.
In order to provide a robust component, the avalanche breakdown is shifted from the edge region of the semiconductor component into the active cell region. For this purpose, compensation regions are also arranged in the edge region of the semiconductor component and have a finer raster there than in the active cell region in order to form an edge termination. What is thereby achieved is that the dopant is distributed more homogeneously in the edge and the intensity of transverse fields is therefore reduced. A semiconductor component of this type is known from DE 101 00 802 C1.
What is problematic in this case, however, is that in order to obtain an even lower on resistance, the compensation structures would have to be miniaturized further in order that the doping levels can be raised correspondingly. However, smaller structures in the lithography planes for producing the compensation zones mean a considerable increase in the fluctuation of the degree of compensation obtained with lithography tolerance remaining constant in the structures produced. Such fluctuations, which result in increased rejects during production, are also intensified by the increase in the doping level since the maximum permitted deviation from the ideal degree of compensation is an absolute quantity. Consequently, the requirements made of the relative accuracy increase proportionally to the higher doping level and the lithography tolerance in the edge zone becomes the limiting element.
For these and other reasons, there is a need for the present invention.